The present invention relates generally to a sheet film package, and more particularly to a sheet film package comprising a tray for storing a plurality of sheet films therein and a light-shielding cover peelably attached to the tray and closing a film access opening, the cover being easily and reliably peelable off the tray in a bright room after the tray with sheet films stored therein has been loaded in a device such as an image recorder.
X-ray photographing devices are widely used in the medical field for recording radiation images of objects such as human bodies on X-ray films by applying X rays to the objects for medical diagnosis. For photographing an object on such an X-ray film, it has been customary to load the X-ray film into an X-ray photographing device under a light-shielded environment and expose the emulsion layer of the film directly to an X ray having passed through the object for recording the image of the object thereon.
There has recently been developed and widely used, particularly in the medical field, a radiation image recording and reproducing system for producing the radiation-transmitted image of an object using a stimulable phosphor material capable of emitting light upon exposure to stimulating rays. When a certain phosphor is exposed to a radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays, or ultraviolet rays, the phosphor stores a part of the energy of the radiation. When the phosphor exposed to the radiation is subsequently exposed to stimulating rays such as visible light, the phosphor emits light in proportion to the stored energy of the radiation. The phosphor exhibiting such a property is referred to as a "stimulable phosphor".
In the radiation image recording and reproducing system employing such a stimulable phosphor, the radiation image information of an object such as a human body is stored in a sheet having a layer of stimulable phosphor, and then the stimulable phosphor sheet is scanned with stimulating rays such as a laser beam to cause the stimulable phosphor sheet to emit light representative of the radiation image. The emitted light is then photoelectrically detected to produce an image information signal that is electrically processed for generating image information which is recorded as a visible image on a recording medium such as a photosensitive material or displayed as a visible image on a CRT or the like.
The visible image thus produced may be recorded on a recording medium by an image recorder such as an image output laser printer, for example. In the image output laser printer, photographic films stored as a recording material in a magazine are loaded, and taken out one by one by a sheet delivery device such as a suction disk or cup. thereafter, the film is exposed to a laser beam modulated by an electric signal produced from the stimulable phosphor sheet for recording an image on the film. The exposed film is then transferred into an automatic developing device and processed thereby to develop the image. The film is thereafter stored in a prescribed place or used for medical diagnosis when required.
When loading the films into the image output laser printer, they must not be exposed to extraneous light. Therefore, it is general practice to load the films into the image output laser printer in a dark room, but the efficiency of such a loading process is low. There is a strong demand for the loading of films under bright conditions such as in an ordinary bright room, and various methods have been proposed for loading films in bright environments. One such method is disclosed in Japanese Laid-Open Utility Model Publication No. 56(1981)-5141.
FIG. 1a illustrates in cross section a conventional sheet film package 1 to be loaded into an image recorder. The film package 1 includes a light-shielded or sunproof container 2 in the form of a box having an opening 2a. The light-shielded container 2 contains a pluraltiy of unexposed films F protected by cardboard 3. A flexible light-shielding member 4 is applied over the opening 2a in light-shielding relation to protect the unexposed films F from exposure to extranous light. One end of the flexible light-shielding member 4 is curved upwardly and has an engagement hole 4a defined near its edge.
The film package 1 of the above construction is positioned by a storage unit 6 housed in a magazine 5 as shown in FIG. 1b. The magazine 5 has a shutter 7 having an engagement pin 8 mounted on one end thereof. After the engagement pin 8 has engaged in the hole 4a of the flexible light-shielding member 4, the magazine 5 is loaded into an image recorder (not shown), and the other end of the shutter 7 is manually pulled out of the magazine 5. As a result, the flexible light-shielding member 4 is peeled off the container 2 by the pin 8 engaging the hole 4a, and the opening 2a is opened in the image recorder. The uppermost unexposed film F is then attracted by a suction device or cup 9 and delivered through the opening 2a into a given photographing position.
With the illustrated conventional device, however, the dedicated magazine 5 must be used to store the film package 1. This magazine must be of a rugged construction capable of withstanding stresses due to repeated attachment and removal thereof, and hence is considerably heavy. Therefore, it is labor some for the operator to load and unload the magazine. The magazine is also considerably expensive since it has a shutter mechanism. Where various films of different sizes are to be employed, there must be used as many dedicated magazines as the number of those different film sizes, and the cost of manufacture is so high that they are economically infeasible in reality.
In order to load the films into the X-ray photographing device, it is necessary to attach the shutter to the end of the film package or the light-shielding member, and pull out the shutter after the magazine has been placed into the device. As a consequence, the film loading process of the above nature is tedious and considerably time-consuming.
In view of the aforesaid difficulties, there has been proposed a sheet film package capable of loading films into an image recorder under bright conditions without using a dedicated magazine, as disclosed in Japanese Patent Application No. 61(1986)-50038. The proposed sheet film package has a tray for storing a stack of films and a flexible cover member peelably attached to the tray. The cover member is bent at one end thereof. The length of the cover member is selected such that when loading the tray into the image recorder, the end of the cover member remains exposed out of the image recorder.
In use, the tray is loaded into the image recorder in a bright room, and then the cover member is peeled off the tray under light-shielded conditions, thus defining a film access opening in the tray. The sheet film package is simple in construction, lightweight, and inexpensive, and any of dedicated magazines which have been in conventional use are no longer necessary.